scholarly journals The role of transcription in EGF- and FSH-mediated oocyte maturation in vitro

2007 ◽  
Vol 98 (1-2) ◽  
pp. 97-112 ◽  
Author(s):  
C.E. Farin ◽  
K.F. Rodriguez ◽  
J.E. Alexander ◽  
J.E. Hockney ◽  
J.R. Herrick ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Maturation In Vitro

scholarly journals Hypoxia-inducible factor (HIF1alpha) inhibition modulates cumulus cell function and affects bovine oocyte maturation in vitro†

2020 ◽  
Author(s):  
Aslihan Turhan ◽  
Miguel Tavares Pereira ◽  
Gerhard Schuler ◽  
Ulrich Bleul ◽  
Mariusz P Kowalewski
Keyword(s):  
Oocyte Maturation ◽  
Cell Function ◽  
Hypoxia Inducible Factor ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Negative Effects ◽  
Protein Levels ◽  
Maturation In Vitro

Abstract Various metabolic and hormonal factors expressed in cumulus cells are positively correlated with the in vitro maturation (IVM) of oocytes. However, the role of hypoxia sensing both during maturation of cumulus–oocyte complexes (COCs) as well as during the resumption of meiosis remains uncertain. HIF1alpha plays major roles in cellular responses to hypoxia, and here we investigated its role during bovine COC maturation by assessing the expression of related genes in cumulus cells. COCs were divided into the following groups: immature (control), in vitro matured (IVM/control), or matured in the presence of a blocker of HIF1alpha activity (echinomycin, IVM/E). We found an inhibition of cumulus cell expansion in IVM/E, compared with the IVM/control. Transcript levels of several factors (n = 13) were assessed in cumulus cells. Decreased expression of HAS2, TNFAIP6, TMSB4, TMSB10, GATM, GLUT1, CX43, COX2, PTGES, and STAR was found in IVM/E (P < 0.05). Additionally, decreased protein levels were detected for STAR, HAS2, and PCNA (P < 0.05), while activated-Caspase 3 remained unaffected in IVM/E. Progesterone output decreased in IVM/E. The application of PX-478, another blocker of HIF1alpha expression, yielded identical results. Negative effects of HIF1alpha suppression were further observed in the significantly decreased oocyte maturation and blastocyst rates from COCs matured with echinomycin (P < 0.05) or PX-478 (P < 0.05). These results support the importance of HIF1alpha for COC maturation and subsequent embryo development. HIF1alpha is a multidirectional factor controlling intercellular communication within COCs, steroidogenic activity, and oocyte development rates, and exerting effects on blastocyst rates.

P–556 NAT10-mediated N4-acetylcytidine in RNA regulates mouse oocyte maturation in vitro

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Y Xiang ◽  
C Zhou ◽  
Q Guo ◽  
X Liang
Keyword(s):  
Mass Spectrometry ◽  
Oocyte Maturation ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Regulatory Role ◽  
Maturation In Vitro ◽  
Rna Immunoprecipitation ◽  
Transcriptional Modulation

Abstract Study question Does NAT10-mediated N4-acetylcytidine (ac4C) in RNA, a newly identified mRNA epigenetic modification, participate in modulating in vitro maturation(IVM) of oocytes? Summary answer NAT10-mediated ac4C modification is an important regulatory factor during oocyte maturation in vitro, by regulating genes associated with translation, mitochondrial functions and protein destabilization. What is known already Unlike somatic cells, transcription and translation are uncoupled during oocyte maturation and gene expression is mainly regulated by post-transcriptional modulation, including mRNA degradation, translation and posttranslational modification, which are complex and have not been fully investigated. RNA ac4C is a newly identified mRNA modification and a key determinant of post-transcriptional regulation, which has been shown to promote mRNA stability and translation, and NAT10 is the only known RNA acetyltransferase. Therefore, NAT10-mediated ac4C represents a possible epigenetic regulator in oocyte maturation. Study design, size, duration Oocytes at different stages from mice were collected to detect the changing levels of ac4C and NAT10 during maturation. NAT10 in GV-stage oocytes was knocked down before IVM, to confirm the regulatory role of NAT10-mediated ac4C in meiotic process, followed by further exploration of cellular mechanisms. Each experiment was repeated at least three times, and data were analyzed by chi-square test, one-way ANOVA or unpaired-sample t-test. Participants/materials, setting, methods The expression of ac4C and NAT10 was detected by immunohistochemistry. NAT10 was knocked down in GV-stage oocytes by RNA interference through electroporation. The efficacy of knockdown was confirmed by qPCR and immunohistochemistry targeting ac4C and NAT10, and the percentages of oocytes maturated in vitro were compared among groups. High-throughput sequencing and RNA immunoprecipitation were performed to reveal the modulated genes. Proteins specifically binding to ac4C sites were identified by RNA pulldown and mass spectrometry. Main results and the role of chance We first retrieved publicly available data from GEO and found that transcripts with potential ac4C sites were enriched in genes downregulated during IVM (P < 0.001). The biased distribution of ac4C implicated a possible regulatory role. Then immunohistochemistry revealed significantly decreasing trends of ac4C and NAT10 expression from immature to mature oocytes. With NAT10 knockdown, ac4C modification was reduced and meiotic progression was significantly retarded. Specifically, the rate of first body extrusion was significantly decreased with NAT10 knockdown (34.6%) compared to control oocytes without transfection (74.6%) and oocytes transfected with control siRNA (72.6%) (p < 0.001), while rates of germinal vesicle breakdown were not affected (P = 0.6531). High-throughput sequencing and RNA immunoprecipitation revealed that the modulated genes were enriched in biological processes known to be associated with oocyte maturation, including translation, mitochondrial translational elongation and termination, and protein destabilization. Also, we identified a series of proteins specifically binding to ac4C probes by RNA pulldown and mass spectrometry, through which ac4C modification may exert its function in post-transcriptional modulation. Limitations, reasons for caution This study was performed in vitro. The role of NAT10-mediated ac4C in vivo remains to be elucidated. Also, limited by current techniques, ac4C modification in oocytes cannot be detected. Our exploration of regulated genes and ac4C binding proteins were performed in somatic cell lines. Wider implications of the findings: Post-transcriptional modulation is crucial in oocyte maturation. Our study using in-vitro systems for mouse oocyte identified NAT10-mediated ac4C as an important regulator in IVM. It provided a new insight into the epigenetic mechanisms of IVM, which may lead to improvement of clinical IVM systems. Trial registration number Not applicable

P-556 Pre-selected for an award: NAT10-mediated N4-acetylcytidine in RNA regulates mouse oocyte maturation in vitro

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Y Xiang ◽  
C Zhou ◽  
Q Guo ◽  
X Liang
Keyword(s):  
Mass Spectrometry ◽  
Oocyte Maturation ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Regulatory Role ◽  
Maturation In Vitro ◽  
Rna Immunoprecipitation ◽  
Transcriptional Modulation

Abstract Study question Does NAT10-mediated N4-acetylcytidine (ac4C) in RNA, a newly identified mRNA epigenetic modification, participate in modulating in vitro maturation(IVM) of oocytes? Summary answer NAT10-mediated ac4C modification is an important regulatory factor during oocyte maturation in vitro, by regulating genes associated with translation, mitochondrial functions and protein destabilization. What is known already Unlike somatic cells, transcription and translation are uncoupled during oocyte maturation and gene expression is mainly regulated by post-transcriptional modulation, including mRNA degradation, translation and posttranslational modification, which are complex and have not been fully investigated. RNA ac4C is a newly identified mRNA modification and a key determinant of post-transcriptional regulation, which has been shown to promote mRNA stability and translation, and NAT10 is the only known RNA acetyltransferase. Therefore, NAT10-mediated ac4C represents a possible epigenetic regulator in oocyte maturation. Study design, size, duration Oocytes at different stages from mice were collected to detect the changing levels of ac4C and NAT10 during maturation. NAT10 in GV-stage oocytes was knocked down before IVM, to confirm the regulatory role of NAT10-mediated ac4C in meiotic process, followed by further exploration of cellular mechanisms. Each experiment was repeated at least three times, and data were analyzed by chi-square test, one-way ANOVA or unpaired-sample t-test. Participants/materials, setting, methods The expression of ac4C and NAT10 was detected by immunohistochemistry. NAT10 was knocked down in GV-stage oocytes by RNA interference through electroporation. The efficacy of knockdown was confirmed by qPCR and immunohistochemistry targeting ac4C and NAT10, and the percentages of oocytes maturated in vitro were compared among groups. High-throughput sequencing and RNA immunoprecipitation were performed to reveal the modulated genes. Proteins specifically binding to ac4C sites were identified by RNA pulldown and mass spectrometry. Main results and the role of chance We first retrieved publicly available data from GEO and found that transcripts with potential ac4C sites were enriched in genes downregulated during IVM (P < 0.001). The biased distribution of ac4C implicated a possible regulatory role. Then immunohistochemistry revealed significantly decreasing trends of ac4C and NAT10 expression from immature to mature oocytes. With NAT10 knockdown, ac4C modification was reduced and meiotic progression was significantly retarded. Specifically, the rate of first body extrusion was significantly decreased with NAT10 knockdown (34.6%) compared to control oocytes without transfection (74.6%) and oocytes transfected with control siRNA (72.6%) (p < 0.001), while rates of germinal vesicle breakdown were not affected (P = 0.6531). High-throughput sequencing and RNA immunoprecipitation revealed that the modulated genes were enriched in biological processes known to be associated with oocyte maturation, including translation, mitochondrial translational elongation and termination, and protein destabilization. Also, we identified a series of proteins specifically binding to ac4C probes by RNA pulldown and mass spectrometry, through which ac4C modification may exert its function in post-transcriptional modulation. Limitations, reasons for caution This study was performed in vitro. The role of NAT10-mediated ac4C in vivo remains to be elucidated. Also, limited by current techniques, ac4C modification in oocytes cannot be detected. Our exploration of regulated genes and ac4C binding proteins were performed in somatic cell lines. Wider implications of the findings Post-transcriptional modulation is crucial in oocyte maturation. Our study using in-vitro systems for mouse oocyte identified NAT10-mediated ac4C as an important regulator in IVM. It provided a new insight into the epigenetic mechanisms of IVM, which may lead to improvement of clinical IVM systems. Trial registration number not applicable

scholarly journals Glycine ameliorates mitochondrial dysfunction caused by ABT-199 in porcine oocytes

2021 ◽  
Author(s):  
Sicong Yu ◽  
Lepeng Gao ◽  
Yang Song ◽  
Xin Ma ◽  
Shuang Liang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
Oocyte Maturation ◽  
Mitochondrial Function ◽  
Protective Action ◽  
Damage Model ◽  
Developmental Competence ◽  
Free Calcium ◽  
Maturation In Vitro

Abstract Mitochondria play an important role in controlling oocyte developmental competence. Our previous studies showed that glycine can regulate mitochondrial function and improve oocyte maturation in vitro. However, the mechanisms by which glycine affects mitochondrial function during oocyte maturation in vitro have not been fully investigated. In this study, we induced a mitochondrial damage model in oocytes with the Bcl-2-specific antagonist ABT-199. We investigated whether glycine could reverse the mitochondrial dysfunction induced by ABT-199 exposure and whether it is related to calcium regulation. Our results showed that ABT-199 inhibited cumulus expansion, decreased the oocyte maturation rate and the intracellular glutathione (GSH) level, caused mitochondrial dysfunction, induced oxidative stress, which was confirmed by decreased mitochondrial membrane potential (Δ⍦m) and the expression of mitochondrial function-related genes (PGC-1α), and increased reactive oxygen species (ROS) levels and the expression of apoptosis-associated genes (Bax, caspase-3, CytC). More importantly, ABT-199-treated oocytes showed an increase in the intracellular free calcium concentration ([Ca 2+]i) and had impaired cortical type 1 inositol 1,4,5-trisphosphate receptors (IP3R1) distribution. Nevertheless, treatment with glycine significantly ameliorated mitochondrial dysfunction, oxidative stress and apoptosis, glycine also regulated [Ca 2+]i levels and IP3R1 cellular distribution, which further protects oocyte maturation in ABT-199-induced porcine oocytes. Taken together, our results indicate that glycine has a protective action against ABT-199-induced mitochondrial dysfunction in porcine oocytes.

scholarly journals Chronological Changes of Bovine Follicular Oocyte Maturation in Vitro

1986 ◽  
Vol 27 (4) ◽  
pp. 505-519 ◽  
Author(s):  
K. P. Xu ◽  
T. Greve ◽  
S. Smith ◽  
P. Hyttel
Keyword(s):  
Oocyte Maturation ◽  
Maturation In Vitro

scholarly journals Requirement of mosXe protein kinase for meiotic maturation of Xenopus oocytes induced by a cdc2 mutant lacking regulatory phosphorylation sites.

1992 ◽  
Vol 12 (7) ◽  
pp. 3192-3203 ◽  
Author(s):  
K M Pickham ◽  
A N Meyer ◽  
J Li ◽  
D J Donoghue
Keyword(s):  
Protein Kinase ◽  
Oocyte Maturation ◽  
Xenopus Oocytes ◽  
Germinal Vesicle ◽  
Cyclin B1 ◽  
Phosphorylation Sites ◽  
Germinal Vesicle Breakdown ◽  
Regulatory Phosphorylation

The p34cdc2 protein kinase is a component of maturation-promoting factor, the master regulator of the cell cycle in all eukaryotes. The activity of p34cdc2 is itself tightly regulated by phosphorylation and dephosphorylation. Predicted regulatory phosphorylation sites of Xenopus p34cdc2 were mutated in vitro, and in vitro-transcribed RNAs were injected into Xenopus oocytes. The cdc2 single mutants Thr-14----Ala and Tyr-15----Phe did not induce germinal vesicle breakdown (BVBD) upon microinjection into oocytes. In contrast, the cdc2 double mutant Ala-14/Phe-15 did induce GVBD. Both the Ala-14 and Ala-14/Phe-15p34cdc2 mutants were shown to coimmunoprecipitate cyclin B1 and to phosphorylate histone H1 in immune complex kinase assays. Microinjection of antisense oligonucleotides to c-mosXe was used to demonstrate the role of mos protein synthesis in the induction of GVBD by the Ala-14/Phe-15 cdc2 mutant. Thr-161 was also mutated. p34cdc2 single mutants Ala-161 and Glu-161 and triple mutants Ala-14/Phe-15/Ala-161 and Ala-14/Phe-15/Glu-161 failed to induce GVBD in oocytes and showed a decreased binding to cyclin B1 in coimmunoprecipitations. Each of the cdc2 mutants was also assayed by coinjection with cyclin B1 or c-mosXe RNA into oocytes. Several of the cdc2 mutants were found to affect the kinetics of cyclin B1 and/or mos-induced GVBD upon coinjection, although none affected the rate of progesterone-induced maturation. We demonstrate here the significance of Thr-14, Tyr-15, and Thr-161 of p34cdc2 in Xenopus oocyte maturation. In addition, these results suggest a regulatory role for mosXe in induction of oocyte maturation by the cdc2 mutant Ala-14/Phe-15.

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